THERMAL AND OXIDATIVE STABILITY OF NONIONIC EMULSIFIERS IN THE PRESENCE OF ALUMINUM AT ELEVATED-TEMPERATURES

Several classes of non-ionic emulsifiers were subjected to high temperature degradation in the presence of aluminum under inert and oxidative atmospheres in a water-hexadecane system. The experimental parameters were selected to simulate catalytic and oxidative conditions in hot rolling of aluminum alloys. The degradation process was monitored by HPLC and GC/MS. Long term exposure to high temperatures in the presence of air resulted in extensive chemical degradation of emulsifiers. Shorter exposure caused chemical transformation of terminal groups and changes in functional properties. The rate of thermal degradation for the emulsifiers was compared to the degradation caused by mechanical shearing.